Koninklijk Nederlands Instituut voor ZeeonderzoekRoyal Netherlands Institute for Sea Research 1 NIOZ is an institute of the Netherlands Organisation for Scientific Research (NWO) Automated FRRF measurements provide an alternative means to obtain seasonal and annual primary production estimates Jacco Kromkamp, Greg Silsbe, Jethro Waanders & Jan Peene

2 Partners in PROTOOL Acknowledgements: EU-FP7-Env program for financing the project 2 Dave Suggett Evelyn Lawrenz Denise Smythe-Wright Diane Purcell/Adrian Rüdiger Röttgers Rodney Forster Eliza Capuzzo Rüdiger Heuermann Karin Munderloh Stefan Simis Pasi Ylostalo Martin Trtilek Michal Sicner Jacco/Greg/Jethro Jan Peene Ondrej Prasil Ondrej Komarek

Why PROTOOL (PRO ductivity TOOL s )  Understanding aquatic ecosystems is not possible without knowledge of primary production  Biomass (chla) is no good measure of primary production (due to high –but varying - turnover rates)  Carrying capacity higher trophic levels depend on primary production, not on chla  Currently no simple PP method, hampering development of long term time series of primary production, certainly by water management agencies  Active fluorescence techniques (PAM-FRRF) are optical techniques, so “easy” to automate  FRRF-based approach can standardize measurements 3

Chl can be measured from space, but turning this into primary production is risky (lack of PI-data, uncertainty ~ 100%) g C/m 2 /yr Composite of annual NPP

Solution: use ships of opportunity and equip it with automated sensors to measure GPP etc? 5  1 year of shipping routes

FRRF basics  F v /F m = indicator of physiological condition of the algae  Relative (!) ETR = PAR x ΔF/F m ’ 6 Max PSII efficiency Effective PSII efficiency F o (proxy for [chla] FmFm’FmFm’ ΔFΔF FVFV Rise in F to F m gives σ PSII

FRRF-basics: the functional and optical cross sections 7  effective = functional PSII cross section: a σ PSII In dark: a PSII

ETR ≠ C-fixation 8  Linear ETR via PSI to NADPH  Alternative electron sinks :  Mehler reaction (water-water cycle)  NO3 reduction  PSI cyclic transport  PSII cycle  PTOX activity 8 Investigate Φ e,C for different water bodies to develop stochastic prediction model

Requirements for PROTOOL: 1. convert ETR into C-fixation 2. integrate ETR of whole water column over time 9 Can be measured with FRRF R-module to measure [chl], k d (z P ),E Unknowns at start project: Φ e,C (mol C/mol electrons) =0.25 mol C/e - n PSII : can now be measured with new Oxborough sigma-algorithm = PSII/chla ETR

Algorithms used 10 K&F algorithm NEW: Sigma algorithm Absorption algorithm (volumetric) 2 new algorithms allow, after proper calibration of n PSII (O 2 - flash yields) measurement of absolute ETR

 Poster Oxborough et al: recent advancements in the methods used to analyse Fast Repetition rate Fluorometry (FRRf) data…. 11 Poster Silsbe et al: Highly resolved measures of photosynthetic electron transport in European coastal waters

Sampling stations monitoring program 12 Oosterschelde = Eastern Scheldt Westerschelde = Western Scheldt Mesotrophic Marine < 2 PSU Secchi:3-5m Eutrophic Secchi: 2-0.2m True estuary: 0-30 PSU

F v /F m as stress indicator  Low F v /F m nutrient limitation (red arrows) and in winter 13

Eastern Scheldt, station OS1, new algorithm no calibration for Φ e,C (0.25)  Some problems with winter values (underestimations), but in general good agreement 14

All data Eastern Scheldt, Φ e,C =

For the Western Scheldt, Φ e,C =

“calibration” of electron requirement for C- fixation based on comparison of daily water column primary production: Eastern Scheldt Seasonality (?) in quantum requirement (QR=1/Φ e,C ) 17

Next step: use annual GPP for QR and average QR over all years. Station specific: example OS2  QR varies between years for some stations  K&F algorithms produced too low QR (<4) 18

Estimates of annual primary production Eastern Scheldt  Annual GPP >90% accurate for new Oxborough algorithms!!  “old” K&F algorithm less reliable 19

Quantum requirements Western Scheldt  K&F algorithm no clear seasonality, but sigma and absorption algorithms show seasonality  Lowest QR April-Sept  Minimal QR<4 20

Western Scheldt: annual GPP as % 14C-GPP  Most estimates % of measured GPP  Cycle in QR?  Something odd with station WS4 21

conclusions  Automated application of FRRF and spectral reflectance makes automated primary production measurements possible  FRRF measurements accurately predict seasonal dynamics in GPP  Quantum requirements (QR) for C-fixation seem rather constant (5-7 in main growth season), but higher in winter (related to low F v /F m ?).  QR are similar for each station, but year to year variation does exist. Reason??? (2006 was odd year in all measurements, also in Westerschelde)  More need to be done to understand variability in QRs  Using autonomous FRRF measurements on SOOPs can significantly improve global GPP estimates  Miniaturize for use on gliders 22

Thank you for your attention suggested reading: 23

Chla is not a good predictor for primary production  Westerschelde estuary: high SPM, eutrophic  Oosterschelde estuary: low SPM, mesotrophic 24

25 Map of chl-a derived through continuous reflectance measurements. The height of the green line is proportional to the chl-a concentration

Project Spectral Reflectance Measurements 26 High spatial resolution (~100 m) characterization of the optical properties and its driving constituents in European Coastal waters.

The fluorometer  Different flow through systems:  direct connection to water inflow  Via storage tank (for dark acclimation or fixed sample) 27

Automated ETR from flow-through 28 Baltic Sea North Atlantic Cruise (England – Iceland)

Acknowledgments:  EU-FP7 program for financing the project  Jan Peene for assistance with the 14C measurements  Partners in PROTOOL 29 Dave Suggett Evelyn Lawrenz Denise Smythe-Wright Rüdiger Röttgers Rodney Forster Eliza Capuzzo Rüdiger Heuermann Karin Munderloh Ondrej Prasil Ondrej Komarek Stefan Simis Pasi Ylostalo Martin Trtilek Michal Sicner Jethro Waanders

PSICAM (point source integrated cavity absorption meter) 30 Data Rüdiger Röttgers, HZG

Example: using a priori assumptions (4 electrons/C and n PSII =0.002 units/mg chla  FRRF accurately captures seasonal dynamics and C-fixation estimates are close to measured one, even using a priori assumptions 31 Centralnorth arm North Sea

Western Scheldt, Φ e,C =0.25  Good performance in both marine and freshwater areas 32

33 Estuaries worldwide Linear relationship between PP and biomass macrobenthos Herman et al. 1999; Kemp et al. 2005